Engineered Cartilage Development using Pulsatile Bioreactors: Influence of Fluid Stress on Matrix Production

 

Articular cartilage experiences dynamic loading during normal activity which can influence the behavior of chondrocyte activity.† Chondrocytes must be cultured in an environment that provides proper nutrients and oxygen while removing waste products.† Cartilage cells live in an environment influenced by mechanical forces, so mechanical forces must also be applied during culturing to produce a phenotypically correct cell response.1† This study was undertaken to investigate in vitro chondrocyte cell response from cryogenically preserved primary bovine chondrocytes in a pulsatile fluid flow environment.† In this experiment, cryogenically frozen bovine chondrocytes were thawed and cultured in monolayer in a serum-based chondrocyte media.† They were seeded by encapsulation within photopolymerized 3-dimensional polyethylene glycol dimethacrylate (PEG-DM) hydrogels.2 The seeded scaffolds were then transferred to a novel bioreactor for 7, 14 and 21 days under varying flow rate conditions.† Chondrocyte extracellular matrix production within the scaffolds was confirmed by Real-Time PCR and histologic analysis.† Real-Time PCR experiments demonstrated up and down regulation of the genes for Type II collagen and Aggrecan as a result of pulsatile flow rate.† Histologic sections stained with hematoxylin-eosin and Alcian blue (for acidic proteoglycans) confirmed matrix formation and chondrocyte viability.† Cellular responses showed that cryogenically preserved chondrocytes retain their ability to redifferentiate and produce extracellular matrix.† The results also showed that pulsatile medium flow had beneficial effects on the cellular activity as compared to static culture which can be used to gain an understanding of the mechanotransduction pathways of chondrocytes.

 

REFERENCES

[1] Martin, I. Obradovic, B., Treppo, S., Grodzinsky, A.J., Langer, R., Freed, L.E., and

Vunjak-Novakovic, G., Biorheology 37: 141-147, 2000

[2] Bryant, S.J. and Anseth, K.S., Journal of Biomedical Materials Research 59: 63-72 2002.

 

Author Name: James A. Cooper Jr.,† Ph.D.

Mentorís name: Marc Cicerone

Division: Polymers 854.03

Laboratory: MSEL

Room and Building address: A109/ Building †224

Mail Stop: 8543

Telephone #301-975-6832

FAX #: 301-975-4924

Email: james.cooper@nist.gov

Are you a Sigma Xi member: no

Category that best describes your poster: Biology